Photographic directional light reference for articulating devices

ABSTRACT

Articulating devices and processes for obtaining photographic images with the articulating device generally include providing the articulating device with a directional light reference for use in photographically obtaining an accurate rendition of a subject being photographed. In this manner, an incidental light reference at the subject location is provided prior to capturing an image of the subject.

BACKGROUND

The present invention generally relates to articulating devices andprocesses for obtaining photographic images with the articulatingdevice. More particularly, the present invention is directed toproviding the articulating device with a directional light reference foruse in obtaining the photographic images.

There is a growing demand for articulating devices capable of providingservices easily to a participant. It is expected that articulatingdevices, e.g., interactive robots, will be able to work in our world,rather than us having to adapt to them. As one can imagine, being ableto accurately capture and process photographic images is important forenabling many of these features, not only for getting around, but fordocumenting events, taking group photos, generating social mediacontent, and performing facial recognition. However, the digital camerascurrently utilized with articulating devices generally lack the level ofdetail and dynamic range associated with the human eye.

Hardware aside, we also take for granted just how much cognitiveprocessing is done with the human mind to parse and interpret imagedata, which is why even some of the most expensive robots still struggleto make sense of, for example, a backlit subject, an array of brightpin-point LED lights, or with figuring out how to interpret an objectstanding in front of an electronic display with a moving picture.

SUMMARY

Embodiments of the present invention are directed articulating devicesand processes for obtaining a directional light reference using thearticulated devices for photography. In one or more embodiments, aprocess for taking a photographic image of a subject includesarticulating at least one articulable appendage coupled to a main bodyof the articulating device to a subject location, wherein the at leastone articulable appendage includes a flat planar surface having thereona directional light reference, and wherein the directional lightreference is at about the subject location; focusing on a predefinedarea of the directional light reference with a camera in the main bodyof the articulating device; adjusting an exposure value within apredetermined range to obtain a desired exposure value; obtaining animage of the predefined area of the directional light reference at thedesired exposure value; processing the image of the predefined area ofthe directional light reference to obtain white balance information atthe subject location; capturing an image of a subject at the subjectlocation using the desired exposure value; and processing the capturedimage with the white balance information to obtain the photographicimage of the subject.

In one or more embodiments, a process for obtaining white balanceinformation for photography using an articulated device includesproviding a directional light reference on a planar surface of anarticulable appendage of the articulated device, wherein the articulableappendage is moveable relative to a main body, the main body comprisinga camera system for digitally capturing an image; articulating thearticulable appendage such that the directional light reference is atabout a subject location, wherein the directional light reference ispositioned to reflect light to the camera system at an angle at a planesubstantially the same as the subject is at the subject location;focusing on a predefined area of the directional light reference;obtaining an image of the predefined area; and processing the image ofthe predefined area to obtain the white balance information at thesubject location.

In one or more embodiments, an articulating device includes a main bodyincluding a camera system configured to capture an image of a subject;at least one articulable appendage coupled with and extendable relativeto the main body, the least one articulable appendage comprising a flatplanar surface having thereon a directional light reference; and acontrol system configured to extend the at least one articulableappendage to about a subject location, wherein the directional lightreference is positioned to reflect light to the camera system at a planesubstantially the same as the subject is at the subject location.

Additional technical features and benefits are realized through thetechniques of the present invention. Embodiments and aspects of theinvention are described in detail herein and are considered a part ofthe claimed subject matter. For a better understanding, refer to thedetailed description and to the drawings.

BRIEF DESCRIPTION DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 illustrates an exemplary articulating device in the form of apersonal robot including at least one articulable appendage coupled to amain body, wherein the at least one articulable appendage includes adirectional light reference.

FIG. 2 is a flow chart of the steps of a method for obtainingphotographic images with the articulating device.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the drawings have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for purpose of clarity.

DETAILED DESCRIPTION

Articulating devices and processes for obtaining photographic imageswith the articulating device generally include providing thearticulating device with a directional light reference for use inphotographically obtaining an accurate rendition of a subject beingphotographed. As will be described in greater detail below, theinformation obtained from the directional light reference and the camerasystem in the articulating device can be used to provide photographicimages with enhanced detail and dynamic range similar to that of thehuman eye. The directional light reference can be a flat object of aneutral gray color that derives from a flat reflectance spectrum such asa digital gray card as the lighting reference, i.e., white balance card,or the like and is integrated onto a planar surface of an articulableappendage of the articulating device such that the lighting referencecan be quickly positioned at the subject image location by thearticulating device prior to taking the subject image picture quicklyand without distracting the subject. Positioning can be effected byarticulation of the appendage to the subject location, movement of thearticulating device to the subject location, or combinations thereof.

The articulating device is not intended to be limited and generallyincludes at least one articulating appendage extending from a base(i.e., body) and a camera system mounted and/or integrated into thebase. The base generally includes a body portion including the at leastone articulable appendage coupled thereto, an optional head portion,optional legs or wheels, and the like to provide the articulating devicewith movement capability from one location to another. For most subjectimages, the camera system and the at least one articulable appendagewill be at an elevated location relative to ground, e.g., at a locationequivalent to a head portion. Moreover, it should be apparent that thecamera system can be mounted and/or integrated anywhere within the baseso long as there is an unobstructed view of the subject. For convenienceand ease in understanding the present application, reference will bemade to a personal robot including a head and at least articulating armextending from an elongated body in a manner and location similar tothat of a human.

An exemplary articulating device in the form a personal robot designatedby reference numeral 10 is depicted in FIG. 1, and as noted above,generally includes a main body 12 and at least one articulable appendage14. The at least one articulable appendage 14 is movable relative to themain body 12. The main body 12 further includes one or more camerasystems, e.g., 16, 18, positioned to have a field of view generallydirected forward. A directional light reference 20, e.g., a digital graycard, is provided on the planar surface of at least one of thearticulable appendages. One or more of the camera systems may beconfigured to capture images and/or video of the robot environment fornavigating the robot 10 and/or performing specialized tasks including,inter alia, photographic imaging of a subject. The robot 10 can includea drive system (not shown) designed to move the robot about in a varietyof environments.

In one or more embodiments, the robot 10 includes a controller incommunication with the at least one articulable appendage, the camerasystem for taking photographic images of a subject, and the drivesystem, if present. The controller may issue commands to one or moremotors to move the articulable appendage, to position the robot from onelocation to another, and to take photographic images in accordance withthe present invention, for example. The controller may also include oneor more computer processors and associated memory systems as isgenerally known.

Likewise, the camera system for taking photographic images in accordancewith the present invention is not intended to be limited and willgenerally include an electronic image capture unit mounted in the mainbody 12 of the articulating device 10. The camera system includes one ormore lens and an electronic array image sensor aligned with the lens. Inpractice, light from a subject propagates along an optical path throughthe lens and strikes the image sensor producing an analog electronicimage. The type of image sensor used may vary, but typically one of theseveral solid-state image sensors available. For example, the imagesensor can be a charge-coupled device (CCD), a CMOS sensor (CMOS), orcharge injection device (CID). A typical image sensor is accompanied byseparate components that act as clock drivers (also referred to hereinas a timing generator), analog signal processor (ASP) andanalog-to-digital converter/amplifier (A/D converter). Such componentscan also be incorporated in a single unit with the image sensor. Forexample, CMOS image sensors are manufactured with a process that allowsother components to be integrated onto the same semiconductor die.

The electrical signal from each pixel of the image sensor is related toboth the intensity of the light reaching the pixel and the length oftime the pixel is allowed to accumulate or integrate the signal fromincoming light. This time is called the integration time or exposuretime. Integration time can be controlled by a shutter that is switchablebetween an open state and a closed state. The shutter can be mechanicalor electromechanical or can be provided as a logical function of thehardware and software of the electronic image capture unit. For example,some types of image sensors allow the integration time to be controlledelectronically by resetting the image sensor and then reading out theimage sensor some time later. When using a CCD, electronic control ofthe integration time of the image sensor can be provided by shifting theaccumulated charge under a light shielded register provided at anon-photosensitive region. This can be a full frame as in a frametransfer device CCD or a horizontal line in an interline transfer deviceCCD. Suitable devices and procedures are well known to those of skill inthe art. Thus, the timing generator can provide a way to control whenthe image sensor is actively recording the image.

The combination of overall light intensity and integration time iscalled exposure. Equivalent exposures can be achieved by variouscombinations of light intensity and integration time.

As used herein, a digital gray card is a middle gray reference that isoften used by photographers to produce consistent image exposure and/orcolor in film and photography. The digital gray card is a flat object ofa neutral gray color density that derives from a flat reflectancespectrum. As will be discussed in greater detail, the digital gray cardcan be integrated onto a planar surface of the extended robot appendageand can be used to provide a directional light reference point that ispositioned in close proximity to the subject image location to set awhite balance point, i.e., a color balance point that takes into accountthe color temperature of the light source, for a particular image setand all images captured thereafter.

By using the available information about a robot's movements, andspecifically, where a calibrated digital gray square will be at aspecific time/place during a pre-programmed movement, it is hereinpossible to greatly improve the image quality of portraits taken byarticulating devices without needing any additional hardware or humanintervention, which provides superior image quality especially indifficult lighting conditions over other auto-exposure methods that arecommonly utilized with articulating devices having camera systems.

There are two forms of light used in photographic imaging systems:reflected light and incident light. Many commercial camera systemsmeasure purely reflected light, which is a measurement of the light thatoriginated at one or more sources of light (window, overhead lamp,camera flash, etc.) that is then reflected off the subject beingphotographed prior to reaching the observer or camera. Existingreflected light solutions largely rely on trial-and-error usingtechniques such as exposure bracketing and image detection, where aseparate process will look for something in the relative shape of thesubject, and refine the exposure from there. These methods can onlyproduce a best guess effort, however, because there is no way to tell ifthe subject is pure gray under a slightly yellow (warm) light, orslightly yellow under a pure white light. Additionally, without areference, the image processor cannot tell the difference between anobject that is dark because it is naturally dark versus an object thatis dark because of poor lighting. Its best guess is to adjust exposureuntil it is “gray”, which is often not an accurate representation and isstill largely trial-and-error in nature.

A fairly popular and well known example of an autonomous robot that hasto make decisions on how to expose for unknown lighting conditions isthe Mars Exploration Rover (MER). This particular robot has a total of10 cameras, which help navigate the MER over the terrain of Mars, withits two main front-facing “eyes” being housed in a so-called PancastMast Assembly. Since the robot's main purpose for imaging is to keep itfrom falling into holes, finding the safest route from one spot to thenext, and taking pictures to send back to Earth for scientists to study,its cameras are programmed with an algorithm to extract the most amountof data from an available scene. It is largely a trial-and-error method,though performed at such a high-speed that it does not contribute to therover's latency. Put simply, camera system generates a histogram ofdetails found at various exposure settings and shifts the exposuresetting until it is gathering the greatest amount of detail. This isvery similar to what an automatic point-and-shoot camera does, thoughthe MER imaging system also allows for manual operation of its exposureprogram, should an engineer want to capture an image for a purpose otherthan strictly collecting data.

In contrast, incidental light measures the light hitting the subjectprior to the light being reflected and reaching the observer or camera.For portraiture and some other forms of photography, an incidental lightreading is greatly preferred as the amount of reflected light does nottake into consideration the coloring of the object or subject beingphotographed. In other words, incident light is the light that falls ona subject, whether it comes from a direct or indirect source.

As an example of the practical differences between the use of reflectedlight compared to incident light when taking a photographic image, asubject with dark skin will reflect less light than someone with lightskin, and a camera that can only measure reflected light will setexposure values differently compared to measuring incident light, whichcan produce markedly different images with the reflected light being aless accurate representation. Even with intelligent scene detection,which is often a feature of current point and shoot camera systems,where a camera can detect or be programmed that a subject image is of ahuman's face, it will still base its exposure on the reflected lightemitted from that person's face, presenting the same problem. However,when incidental light is used as a reference measurement, thephotographer can be assured that the subject image captured by thecamera system will be a true representation of the shade and color ofthe subject, and not the camera's attempt to create something safelyaverage as defined by the cameras processing algorithms for theparticular subject setting, e.g., portrait, landscape, beach, fireworks,moving subjects, and the like.

Professional photographers typically measure incident light with lightmeters, which electronically determine the ideal exposure and whitebalance point for a specific point of view. These devices are veryhelpful, and would prove to be an ideal solution were they not so largeand typically expensive. Moreover, integrating a light meter into anarticulating device such as a robot would likely add cost, bulk, andcause a loss of dexterity. Providing a direct light reference onto aplanar surface of an articulable appendage is of minimal cost, easilyintegrated, and provides improved accuracy relative to the trial anderror techniques utilized in articulating devices configured to usereflected light for image processing.

Articulating devices such as robots can be highly precise in theirmovements, and as such, can carry out a movement or a reaction that mayseem natural and fluent, while still being calculated down to themillisecond in time, and millimeter in movement. This is beneficialbecause many robots need to operate within a specified and limited areawithout interfering with the surrounding landscape, e.g., storedisplays, doors, other robots, or the like. The present invention takesadvantage of the programmed movements of the robot, and the fact thatthe location and time are known parameters such that one can quickly andconsistently obtain a direct light reference for the available lightthat is illuminating a subject to be photographed. The benefits arethree-fold. First, the robot is able to obtain a direct light referencereading such that the images the robot uses will be exposed and coloredcorrectly for that exact lighting condition. Secondly, the reading willtake place in a way that may not be noticed by the subject, therebymaintaining the illusion of the robot being thoughtful and cognitive,and third, the method of photographically obtaining an accuraterendition of the subject requires no additional hardware. Instead, onlya relatively small flat area on one of the robot's articulableappendages is used, wherein a directional light reference is provided onthe small flat area. The size of the directional light reference willgenerally depend on the resolution provided by the camera system.

When implemented, the robot gains additional functionality which allowsfor the operator to program a series of movements that incorporate themeasuring of the reference spot that can then be used to set a whitebalance point, i.e., color balance point, for a particular image and allimages captured thereafter at that location. The act of measuring thereference spot is performed shortly before a photographic image of thesubject is taken, and can be done in such a way that does not distractor take-away from the experience. When in use around subjects, thesubject or operator of the robot are not required to do any additionaltasks in order to initiate this feature beyond what would normally berequired to start a “picture-taking” behavior. Moreover, the robot canbe moved into position such that extension of the articulable appendagecan provide a measurement of the reference spot at the particularsubject location.

In this manner, the robot programmer knows or can determine ahead oftime exactly when and where the reference spot should be measured duringthe robot's movement. This can be set during programming by steppingthrough the range of motions and isolating a single frame and thenselecting the spot. This point can then be saved as a reference, alongwith other information about the particular movement, which can beleveraged by any other user who is using that particular movement. Onceset, using the reference spot in a programmed movement can obtain theincident lighting reference quickly, therefore eliminating problemsassociated with backlighting, high-contrast lighting, and othersituations that may confuse a digital camera's image processor.

This solution is unique to highly-articulated and precise robots, whichcan take advantage of a tightly-controlled range of motion. In thesesystems, one instance of a movement is not only visually identical fromthe next, but we can leverage this feature to reliably obtaininformation about the environment that the robot is in without the needfor additional hardware. The constant of the reference spot, a flat areawith a medium-grey color, with the known location of that spot duringthe timeline of a movement, enables the articulating device to obtain alight reference similar to the way a photographer uses a digital greycard, only with the added benefit of the measurement being integratedinto an existing movement, like waving to a subject who wants theirpicture taken, or who needs to be identified with facial recognition.

In one or more embodiments, a reference spot will be provided on a flatsurface of the appendage, typically the back of its “hand” or arm. Itshould be apparent to those skilled in the art that the higher theresolution of the camera, the smaller the spot can be, but it needs tobe sufficiently flat, evenly colored/shaded, and placed at the referencespot such that it reflects light at an angle similar to the same planethat the subject will be situation. For example, if the directionallight reference were pointed up towards the ceiling, a false readingcould be obtained from an overhead light, when the light that mostaffects the picture is coming from behind the robot.

In one or more embodiments, the robot can be configured to access areferenceable time and position for where to find the reference spotduring its movement. By way of example, a programmer can use a timelineviewer/editor, common to most robotic programming software, to modifythe available motions. By selecting a portion of a movement where thereference spot is plainly visible, and in close proximity to where thesubject will be, for example, waving or giving a high-five, they canidentify a time (key frame) and space (area of the image from thebuilt-in camera) to quickly and programmatically obtain the necessarylighting reference.

FIG. 1 provides a flow chart detailing the process for obtainingphotographic images with an articulating device using a directionallight reference. The process begins at step 100, wherein thearticulating device, e.g., robot, is initiated. As noted above, thearticulating device generally includes a body portion including a camerasystem and at least one articulable appendage coupled to the bodyportion. The photographic imaging process generally begins withinitiating light measurement movement with the articulating device asindicated at step 200.

In step 300, the articulating device waits until the position matches apredetermined location at which point it provides a trigger for thedirect light reference. Positional and/or time information can begathered in steps 302 and 304.

In step 400, once the direct light reference is at the triggeredlocation, the camera system can be configured to utilize a pre-definearea of the direct light reference, which as noted above is a flatneutral surface, e.g., a digital gray card, of the articulable appendageextending from the body portion of the robot.

In step 500, the camera is adjusted to the appropriate exposure valueassuming the value is within a defined range. If outside the exposurevalue range as indicated in step 600, exposure bracketing at differentbrightness levels can be used. For example, shutter speed in the camerasystem can be increased and decreased to provide different brightnesslevels.

In step 700, a determination can be made as to whether the exposurevalue obtained from the direct light referenced provides adequatereference information. Once adequate reference information is acquired,processing of the reference point information can begin for whitebalancing. The camera will then read and lock in the color temperatureof the light reflected from the direct light reference, e.g., gray card,and that locked-in reading now becomes the standard for the camera'swhite balance setting.

If adequate reference information is not provided as indicated in step802, the process can be repeated until such time that adequate referenceinformation is acquired. Optionally, an alternate light measuringmovement can be initiated.

In step 900, the exposure value and the white balance information isthen used tor image processing.

In step 1000, a photographic image is then taken of the subject at thecorrectly determining exposure setting.

In step 1100, the captured image is then processed with the appropriatewhite balance setting information that had previously been obtained.

In low-light situations, it may be beneficial to ensure that themovement is not too fast where the shutter speed is too slow to catchthe spot accurately. In these embodiments, the movement can be sloweddown, or a backup movement can be used that is easier to measure. Again,because the size of the reference spot, current shutter speed, anddistance between the camera and reference spot are known variables, itis possible to interpolate if the current light and movement allows foran accurate measurement. For example, the default animation may be awaving of the hand, and the backup animation for low-light may be ahigh-five or thumbs up.

Once the image of the reference spot is obtained, the direct lightreference data can be used to correctly expose and color any futureimages taken in the same location under the same lighting, and theinformation can be leveraged by the image processor for any number ofimage-based tasks.

The following definitions and abbreviations are to be used for theinterpretation of the claims and the specification. As used herein, theterms “comprises,” “comprising,” “includes,” “including,” “has,”“having,” “contains” or “containing,” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, acomposition, a mixture, process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but can include other elements not expressly listed or inherentto such composition, mixture, process, method, article, or apparatus.

As used herein, the articles “a” and “an” preceding an element orcomponent are intended to be nonrestrictive regarding the number ofinstances (i.e. occurrences) of the element or component. Therefore, “a”or “an” should be read to include one or at least one, and the singularword form of the element or component also includes the plural unlessthe number is obviously meant to be singular.

As used herein, the terms “invention” or “present invention” arenon-limiting terms and not intended to refer to any single aspect of theparticular invention but encompass all possible aspects as described inthe specification and the claims.

As used herein, the term “about” modifying the quantity of aningredient, component, or reactant of the invention employed refers tovariation in the numerical quantity that can occur, for example, throughtypical measuring and liquid handling procedures used for makingconcentrates or solutions. Furthermore, variation can occur frominadvertent error in measuring procedures, differences in themanufacture, source, or purity of the ingredients employed to make thecompositions or carry out the methods, and the like. In one aspect, theterm “about” means within 10% of the reported numerical value. Inanother aspect, the term “about” means within 5% of the reportednumerical value. Yet, in another aspect, the term “about” means within10, 9, 8, 7, 6, 5, 4, 3, 2, or 1% of the reported numerical value.

It will also be understood that when an element, such as a layer,region, or substrate is referred to as being “on” or “over” anotherelement, it can be directly on the other element or intervening elementsmay also be present. In contrast, when an element is referred to asbeing “directly on” or “directly over” another element, there are nointervening elements present, and the element is in contact with anotherelement.

The flow diagrams of the figures depicted herein are just examples.There may be many variations to these diagrams or the steps (oroperations) described therein without departing from the spirit of theinvention. For instance, the steps may be performed in a differingorder, or steps may be added, deleted or modified. All of thesevariations are considered a part of the claimed invention.

It will be understood that when an element, such as a layer, is referredto as being “on” or “over” another element, it can be directly on theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly on” or “directly over”another element, there are no intervening elements present.

While the present invention has been particularly shown and describedwith respect to preferred embodiments, it will be understood by thoseskilled in the art that the foregoing and other changes in forms anddetails may be made without departing from the spirit and scope of theinvention. It is therefore intended that the present invention is not belimited to the exact forms and details described and illustrated butfall within the scope of the appended claims.

What is claimed is:
 1. A process for taking a photographic image of asubject, the process comprising: articulating at least one articulableappendage coupled to a main body of an articulating device to a subjectlocation, wherein the at least one articulable appendage comprises aflat planar surface having thereon a directional light reference, andwherein the directional light reference is at about the subjectlocation; focusing on a predefined area of the directional lightreference with a camera in the main body of the articulating device;adjusting an exposure value within a predetermined range to obtain adesired exposure value; obtaining an image of the predefined area of thedirectional light reference at the desired exposure value; processingthe image of the predefined area of the directional light reference toobtain white balance information at the subject location; capturing animage of a subject at the subject location using the desired exposurevalue; and processing the captured image with the white balanceinformation to obtain the photographic image of the subject.
 2. Theprocess of claim 1, wherein obtaining the image of the predefined areacomprises referencing positional information and time of movement of theat least one articulable appendage; and obtaining the image of thepredefined area at about the subject location based on the positionalinformation and time of movement.
 3. The process of claim 1, whereinwhen the desired exposure value falls outside the predetermined rangethe process further comprises bracketing by taking multiple images ofthe predefined area of the directional light reference at differentexposure values; and selecting the desired exposure value from thedifferent exposure values.
 4. The process of claim 3, further comprisingrepeating the step of adjusting the exposure value associated with thepredefined area to obtain the desired exposure value if the desiredexposure value is not obtained by the bracketing.
 5. The process ofclaim 1, wherein the directional light reference is on a planar surfaceat a distal end of the at least one articulable appendage.
 6. Theprocess of claim 1, wherein articulating the at least one articulableappendage positioned the directional light reference to reflect light tothe camera system at an angle at a plane substantially the same as thesubject is at the subject location.
 7. The process of claim 1, whereinarticulating at least one articulable appendage is integrated with anexisting programmed movement of the articulating device.
 8. A processfor obtaining white balance information for photography using anarticulated device, the process comprising: providing a directionallight reference on a planar surface of an articulable appendage of thearticulated device, wherein the articulable appendage is moveablerelative to a main body, the main body comprising a camera system fordigitally capturing an image; articulating the articulable appendagesuch that the directional light reference is at about a subjectlocation, wherein the directional light reference is positioned toreflect light to the camera system at an angle at a plane substantiallythe same as the subject is at the subject location; focusing on apredefined area of the directional light reference; obtaining an imageof the predefined area; and processing the image of the predefined areato obtain the white balance information at the subject location.
 9. Theprocess of claim 8, wherein the directional light reference is on aplanar surface at a distal end of the articulable appendage.
 10. Theprocess of claim 8, wherein obtaining the image of the predefined areacomprises referencing positional information and timeline of movement ofthe articulable appendage; and obtaining the image of the predefinedarea at a referenced position and at a specific time within thereferenced timeline of movement.
 11. The process of claim 8, wherein thedirectional light reference is a digital gray card.
 12. The process ofclaim 8, wherein articulating at least one articulable appendage isintegrated with an existing programmed movement of the articulatingdevice.
 13. The process of claim 8, wherein obtaining the imagecomprises adjusting an exposure value within a predetermined range toobtain a desired exposure value.
 14. The process of claim 13, whereinwhen the desired exposure value falls outside the predetermined rangethe process further comprises bracketing by taking multiple images ofthe predefined area of the directional light reference at differentexposure values; and selecting the desired exposure value from thedifferent exposure values.
 15. An articulating device comprising: a mainbody including a camera system configured to capture an image of asubject; at least one articulable appendage coupled with and extendablerelative to the main body, the at least one articulable appendagecomprising a flat planar surface having thereon a directional lightreference; and a control system configured to extend the at least onearticulable appendage to about a subject location, wherein thedirectional light reference is positioned to reflect light to the camerasystem at a plane substantially the same as the subject is at thesubject location.
 16. The articulating device of claim 15, wherein thearticulating device is a person robot.
 17. The articulating device ofclaim 15, further comprising a drive system for moving the articulatingdevice from one location to another.
 18. The articulating device ofclaim 15, wherein the directional light reference is a digital graycard.
 19. The articulating device of claim 15, wherein the main bodycomprises a head portion, and the camera system is located in the headportion.